Glomalin production after grazing simulation.

<p>Glomalin production per mg hyphal dry weight in <i>G. intraradices</i> in <i>in vitro</i> culture, as a response to rising intensity in mechanical injury of the hyphae, induced by clipping. The injuries had to be undertaken on an existing mycelium and was therefore not present since experimental start as in the salinity and osmolarity treatments. Intensities should therefore not be directly compared.</p

Growth morphology of <i>G. intraradices</i> under high osmolarity.

<p>Growth morphology of <i>G. intraradices</i> growing in untreated M-medium in <i>in vitro</i> culture (a, c) and under high osmolarity (b, d), as here under 250 mM glycerol addition. Scale bars 1000 µm (a, b) and 200 µm (c, d). Spore abundance and diameter are reduced, and hyphae show curly growth morphology under high glycerol addition.</p

Glomalin production under salt- and osmotic stress.

<p>Glomalin production per mg hyphal dry weight in <i>G. intraradices</i> in <i>in vitro</i> culture, as a response to rising salinity as induced by NaCl addition (a) and rising osmolarity as induced by glycerol addition (b) into the growth medium.</p

AM fungal mycelium biomass under salt- and osmotic stress.

<p>Mycelium biomass [mg dw] of <i>G. intraradices</i> in the fungal compartment in <i>in vitro</i> culture, as a response to rising salinity induced by NaCl addition (a) and osmolarity as induced by glycerol addition (b) into the growth medium.</p

DataSheet1_Microplastics of different shapes increase seed germination synchrony while only films and fibers affect seed germination velocity.docx

Microplastics enter the soil in a variety of shapes and polymer types altering soil properties with known consequences for plant growth. However, the effects of a range of different microplastic shapes and types on seed germination are mostly unknown. Here, we established a glasshouse experiment that included 12 microplastic types representing different shapes (fibers, films, foams and fragments) and polymers, and mixed each of them with soil at a concentration of 0.4% (w/w). Fifty seeds of Daucus carota were sown and monitored for 49 days to evaluate different germination parameters. Our results showed that microplastic films and fibers decrease seed germination velocity as they may affect soil water status, likely interfering with different phases of seed germination: Seeds may imbibe toxic microplastic leachates, and be affected by a physical blockage; testa rupturing may be delayed as this also depends on water uptake. Microplastic toxic leachates may affect activity of enzymes key for seed germination, and delay embryo growth and radicle emergence. Microplastics, irrespective of their shape and polymer type, increase synchrony of seed germination, which might be linked with microplastics exerting a mild stress on seeds. The final percentage of germination was not affected by microplastics in soil, implying that microplastics did not affect seed viability. Our results showed that microplastics affect seed germination mainly as a function of their shape.</p

As <b>Fig. 3</b> but for the intermediate niche breadth.

<p>As <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0035942#pone-0035942-g003" target="_blank"><b>Fig. 3</b></a> but for the intermediate niche breadth.</p

Typical Tuscan countryside near Siena (Italy).

<p>The pictured landscape is known as “Le Crete” and is characterised by gentle hills and slopes. This photo demonstrates the concept of an environment with multiple spatial structures (<i>sensu</i> Borcard et al. 2004). In the picture, one can clearly see a linear trend corresponding to the average slope of the terrain but also a sinusoidal pattern in the way hills and valleys alternate along the linear gradient. We used this view for simulating the continuum hypothesis in a spatially structured landscape. Credit: Giuseppe Manganelli, University of Siena.</p

Six of the simulated communities after 5000 time steps.

<p>Beside each simulated landscape, mean (± S.E.) standardised effect size are reported with data stratified by type of null hypothesis (neutral <i>vs.</i> null) and sampling design. For the neutral analysis, a positive effect size means that local communities under the effect of the niche are more dissimilar than their neutral counterpart (i.e., niche switched off by nullifying niche differences). For the null model, a positive effect size means that species are co-occurring less than expected by chance (segregation). Here we present the results for narrow niche breadth stratified by dispersal (rows) and noise (columns). In the top left corner, low levels of dispersal and noise produce clearly visible spatial patterns that become more confused (see also <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0035942#pone-0035942-g004" target="_blank">Fig. 4</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0035942#pone-0035942-g005" target="_blank">Fig. 5</a>) as noise and dispersal are increased. In the bottom right corner, parameter settings are opposite to the top left corner and species distributions appear highly stochastic, even though a careful visual examination of the gray tones reveals some perceivable spatial patterns in terms of the periodic component. Results are reported for the analysis performed between the two latitudinal strata (north and south). The results for the analysis performed within a latitudinal stratum are reported in the supplementary material and reinforce patterns visible in this figure and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0035942#pone-0035942-g004" target="_blank">Fig. 4</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0035942#pone-0035942-g005" target="_blank">5</a>.</p

Spatial distribution of the niche axis, which is the parameter determining propagule survival (see addition methods in the supporting information for a quantitative description).

<p>From white to black, the niche <i>E</i> ranges from value one to 100. On the left panel, the systematic component in the spatial distribution of <i>E</i> is shown: a linear trend makes the niche having light tones in the south and progressively darker tones toward the north; further, a periodic component was added, that generates a sinusoidal-like patterns (compare to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0035942#pone-0035942-g001" target="_blank">Fig. 1</a>). Panels in the middle and the right sides show the effect of adding respectively low (range of uniform distribution = 10) and high noise (range = 100) to the pattern on the left side. Even when the noise is high (right side), some spatial pattern is still visible.</p

As <b>Fig. 3</b> but for the broad niche breadth.

<p>As <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0035942#pone-0035942-g003" target="_blank"><b>Fig. 3</b></a> but for the broad niche breadth.</p